Have you considered this approach (assuming you could deploy a solution package - even Sandbox should be fine):

Create your own Content type based on Document. No need to actually
add aditional properties. Add this content type to your library and
remove the default Document.

Create a Custom Action feature which is targetting Content Types (using RegistrationType and RegistrationId attributes) and hides respective actions (to identify the actual location and Id of the Settings check this file on physical SharePoint server C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\GLOBAL\XML\CMDUI.XML see here an example http://www.3guysonsharepoint.com/?p=778). As a result every time you use the XSLTListView in any page the same would apply for your library and buttons would get hidden. Of course, savvy users could always target the Library Settings application page, unless you actually use Permissions to restrict that.